Three armyworm species occur in South Africa: the fall armyworm (Spodoptera frugiperda), the African armyworm (S. exempta), and the lesser armyworm (S. exigua). These insects’ life cycles, behaviour and ecologies differ, and they feed on different crops, says Dr Annemie Erasmus, a senior researcher of entomology at the Agricultural Research Council’s (ARC) Grain Crops Institute.
The lesser armyworm, for example, survives on broadleaved plants, while the African armyworm feeds on grass species such as maize.“It is essential for crop producers to familiarise themselves with the different species of armyworm to ensure correct classification and effective control should an outbreak occur,” says Erasmus.
Fall Armyworm
Fall armyworm (FAW) larvae were first collected in South Africa in 2017, mainly on maize lands. The pest can cause great devastation to a number of different crops.
Its life cycle varies between 24 and 30 days, depending on prevailing temperature and humidity, and the number of generations that appears in an area is determined by the number of dispersing moths.
FAW does not have a diapause (overwintering) stage. The moths lay eggs, which are domeshaped, have a flat base and curve upwards to a broadly round point, in batches on foliage. Up to 200 eggs in a batch have been recorded, and a moth can lay more than 1 000 eggs in her lifespan.
The female deposits a layer of furry-looking, greyish scales over the egg batch. The egg stage lasts two to three days.
Newly hatched larvae are green, but their colour changes as they mature. The smooth-skinned larvae range from light tan or green to nearly black, with three yellow-white lines running down the back. On each side of the body are yellow lines and a wider dark stripe.
Diese Geschichte stammt aus der Farmers Weekly 6 March 2020-Ausgabe von Farmer's Weekly.
Starten Sie Ihre 7-tägige kostenlose Testversion von Magzter GOLD, um auf Tausende kuratierte Premium-Storys sowie über 8.000 Zeitschriften und Zeitungen zuzugreifen.
Bereits Abonnent ? Anmelden
Diese Geschichte stammt aus der Farmers Weekly 6 March 2020-Ausgabe von Farmer's Weekly.
Starten Sie Ihre 7-tägige kostenlose Testversion von Magzter GOLD, um auf Tausende kuratierte Premium-Storys sowie über 8.000 Zeitschriften und Zeitungen zuzugreifen.
Bereits Abonnent? Anmelden
Syngenta Seedcare celebrates a decade of innovation
Syngenta's ambition is to enable their customers' investments to grow in healthy soil from treated seeds to young plants through innovation and collaboration, writes Magda du Toit.
Agri workers shine at Western Cape awards
Lindie-Alet van Staden, a garden and olive orchard manager at L’Ormarins Wine Estate in Franschhoek, was crowned as the Western Cape Prestige Agri-Worker of 2024 at a gala event recently held near Paarl.
Small and large farmers recognised at grain awards
The annual Grain SA/Syngenta awards ceremony bears testimony to the quality of farmers in the grain industry.
Growing partnerships: Fedgroup's flexible and innovative approach
Janine Ryan spoke to Warren Winchester, general manager of impact investing at Fedgroup, about why the company became involved in agriculture, and what it offers farmers and their immediate communities.
Why fish farms fail, and how to avoid becoming a statistic
The popularity of launching fish farms is not matched by their success. Leslie Ter Morshuizen, owner of Aquaculture Solutions, explores the factors that cause most of these businesses to go under.
Where history and modernity meet in a luxurious setting
Brian Berkman kept his eyes peeled for ghosts in the oldest continuously run hotel in South Africa, but all he found was a fabulous two-night stay.
THE HITCHING POST
I'm a stylish elderly lady with a radiant glow and a good sense of humour that keeps me young at heart.
Cutworms: check the weeds on your fields!
Zunel van Eeden explains why understanding the ecological interplay between cutworms and weeds is crucial for effective pest management. Producers should disrupt the life cycle of cutworms to minimise crop damage.
Does high-density grazing mimic grazing patterns of game?
In their paper on high-density grazing in Southern Africa, professors Angelinus Franke and Elmarie Kotzé from the Department of Soil, Crop and Climate Sciences at the University of the Free State say high-density grazing systems may not accurately reflect natural ecosystems. Roelof Bezuidenhout reports.
Global grain outlook: 2024/25 marketing season
In its latest summer crops report, the Crop Estimates Committee says South African farmers intend to plant 4,47 million hectares of summer grains and oilseeds in the 2024/25 season, up 1% from the previous season. As South Africa exports maize and soya bean, Annelie Coleman reports on the latest trends in the international grain and oilseed markets, amid fluctuations in weather conditions and ongoing armed conflicts.
